Telephone system.



H. G. WEBSTER.

n TELEPHONE SYSTEM. APPLIOATION rILIm JULY 16,1996.

Patented Aug'. 8,1911.

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I apparatus for systems of this class in which x systems heretofore proposed.

`mission and signaling is furnished froma y UNITED Sill/xTl-lt PATENT OFFICE.

HARRY G. WEBSTER, 0F CHICAGO, ILLINOIS, ASESIGNOR, BY MESNE ASSIGNMENTS, TO KELLOGG SWITCHBOARD & SUPPLY COMPANY, A CORPORATION 0F ILLINOIS.

TELEPHON E SYSTEM.

Specication of Letters Patent.

Patented Ayug. 8, 1911.

Application led July 16, 1906. Serial No. 326,502.

To all whom it may concern:

Be it known that I, HARRY G. lVnns'rnn, a citizen of the United States, and resident of Chicago, county of Cook, and State of Illinois, have invented certain new and useful Improvements in Telephone Systems, of which the following is a full, clear` concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

My invention relates to telephone exchange systems in which current for trans-v central source located at the exchange, and in which the cut-olf relay, which controls the normal connections of the line, is actuated by current iiowing over a portion of the talking circuit when a link-conductor is wnnected with the spring-jack or switching terminal of the line.

It relates `particularly to systems of this character in which-the source or sourcesof current which serve to energize the substation transmitters may be associated with the cord connection apparatus only; Iand may be distinct and separate' from t at source as sociated with and furnishing current for the actuation of the apparatus which is individual to the various line circuits.

The object of my invention is to provide an improved organization of circuits and the circuit of the transmission source or that associated with the link-conductor, is so or aniz'nd with relation to the circuit of the ine battery or that source which furnishes current for the energization of the cut-off relay, that although the-two separate sources have their circuits completed over the same. 'strand of the cord circuit and are both connected to common conductors at the xchange, no interference between the -two sources will result.

A further object of the invention is thev provision of such a circuit arrangement in a structure of this character that the resence of an earth connection upon a line imb, external to the central office, will not cause the cut-olf relay 'to be energized b current from the central source after the isconnec- .tion of the link-conductor from the spring jack, this being an objectionable feature 1n My invention' will be more fully underterminal which is inactive as far as a circuit to earth is concerned.

Referring to the drawing the subscribers apparatus 1s shown at A as consisting of a hooked switch k normally including signal bell-b and condenser c in bridge of the line limbs and when moved to its alternate or raised pcsiticn. closing an alternate bridge of the line through transmitter z* und receiver fr. Although I show but one substa tion arrangement, it will be understood by those skilled in the art that various other arrangements of the apparatus muy be used and I do not confine myself to the particular arrangementillustrated. Under normal conditions the receiver hangs upon its hook switch maintaining its upper contact o en and the condenser c prevents a normal ow of current from line battery C2 at the central office through the line lim-bs.

The cut-olf relay 5 is prevented from being held up by current throughan accidental ground of the line limb, by connecting the battery with which it is associated in Vopposition to the battery which furnishes current for transmission. The battery C' with which the relay 5 is connected may be of the same or somewhatdower potential than the transmission battery F.

The subscriber calls in the usual way bremoving receiver r from its, switch hook thus ener 'zing relay 3 by current from batteryfC2 owing over line limbs 1 and 2 to ground at upper contact of relay 5, thus lighting'line lamp 4, and when the answering plug O is inserted into the jack, cur rent from terminal 27 of battery C' will flow through relay 11, strand 7, contact 22 and the winding of relay 5 t terminal 26 of the battery, operating the relay and connecting the line 'limbs to the spring-jack terminals I t is evident 4that if limb 1 of the line be grounded at this time and the answering plug he wouhl tent] to flow through winding and through the lower armature anll normally open Contact of thLl rela)y to linut., 't and grouuil if it were not rfor the opposing ptliteutial of hattetr l". the opposingr potential ot this hattery prevents sueh flow anll if the litl'erenee in po teutial hetween the two hatlerie` he Hiltieientl)Y great will eause a reversal of eur rent in lthe. whalingr of rela)y is removed, thus nionwntariltr (lea|er; 1iv.in Ll thel rela)v ancl allowing the armature to ll'op hack and (liseonneel the relay from the line. The operator haring anrweretl thtl e: tl lo' inserting plu; y (i) into a lapringf jeehY j. eul'- rent will flou* from the aetire ple of `hatterlv l" through the winding: ot' relay ll. .Qlranlt T. sleeve eontaets of pluLr o alul jaelt' Ii. lille linlh l. ,nth-lation returning;- over line linih L anti tip "onllurtor of jaek j. Strand t', aint through relay 101i) eroutulell pole ol' battery l". Thus hoth of the relate ttl anrl lt living energized laxrp 1l is; not lighted. 'ille operator now proeeethr to test the ealletl for line in tln' ton'zlling the tip ot plug l. the iaek of the icllqs the eontaet 22 of the line. tes-tell is at the potential of terminal Qt', ot hat'teluv :1S is also the tip of the milling plug! l. Tf the line he busy. the eonsmluent fliterenee of potential will Cause. a flow oF eurrent to the tip of the plug. strand 8, armature QS mul eontaet4 29 of rela)v the eonnnon test whaling torL, in -uetion eoil toterntinal 26 battery. Assuming the milled for line is itlle the, operator spring: jaek of the eallefl line, thereby energizing relay lf and the eut-off rela)v T of the Called line. hy eurrent from battery t" the u'ixulhrslr of relay 151', strand .t. plug,lr antl jat-l: ulcere eontaets and winding of the eutotl` relay to terminal 26 of battery C. The operation of rela)r in, y 5&2 from the tip Stranri of the eortl eir enit at eontaet 29 a ntl closing! of contar-ts QQ. 30. etl'eetive to eause continuity of strarul 8. The operator now presses ringing keys to the, sleeve fit of the opera- .i when the plugl eallerl line am] if the line he 13 (lisemmeets the witul removed, Current l ing lamp 15. from ternnnal Ztl hnishetl muret-Hatton, hy replaffing their reu ual manner hy After the sul'saeriliers have eeirers upon their witeh hooks the eireuits tor relays i0 anfl l2 are interrupted. there h r tleuerglizingr the Saill relay amt lighting lamps ll alul lf. 'l`he operator iu responee to this Signal removes plugs t) an. l" front the spring pal'atua to uorlnal. 'hile l ani not lintilefl to fapeetie r .-i ta1ue:- :unl \o|ta; e iu thi arrangeluent, l hare 't'oantl that the halter); t" may have a potential ot' 1S or '2H volts. that hattelv l" |n:\ have a potential ol' il volts. while the relay T thatl he ot' LII() ohms re i tanee an'tl rela 'ttl anll tl of UN) olnns ear-h. lt will he er'uleut that the hattet-y ("'g whieh is shown as ruppllring ent-rent for the relay 2l may he repla-eeil lo' a uilallle ronneetiou troni halter)I l". l il ln the strutture illu-tr|te l it will he seen that the hattery whit-h supplies eurrent for the euergzaton of the eut-ott relay naar he of lower voltaire than that nhieh lwirres to energize the transmitter at the salatation: that when the line i# ronneeteil fot 1tm\er1 atton the two hat1erie:- have their 1| eireuit eonipletetl through a eornluetor rom- 13 anil thence. through of the inserts plug: P into the reeeirer froluits' iewiteh hook then-h),1 eale` v in; r a path for tlireet euri-ent i. to hattery lt over the ltlnlas of the telephone line. retui-nlug;r through supervisory relay 1". to

'round enereiziner rela 1 12 and extin ruishthe closing of eoutaet 3l.

Although mon to hoth: :nul that ther are alfa hath emmet'texl to l'routnl or to the otlit'e )'ettltl. '|"he YariouQ |e\:i,-tanee\A an l \'olta;e are -o proportioneil however. that eurrent from tlm. tranenieeion hattery flee@ not tlow through the eut-off relay. antl the :Quhstation lran 1nitter itherefore not unlluhv hunted h Y the prefeuee oi` the eut-oil' rela)Y whaling eouueeteil tothe line liinl): und the rireuit .is so lialanr'etl that the propel' eurrent' iS prorilh'tl t'or tmnsniion :unl for the operation ol' the various parts: of the apparatus. lt is'also seen that the r'it'euit ot the eutAott' rela \y is under alisolute eontrol ot' the operator :intl that the relay will not' he loelietl up hy the pregenee of an earth eonneetion to the line litnh. lt will he unilerstoocl that the rai-ion. earth eonner'- tion# shown are or ma)Y he eonneetions to the ofliee return whieh or|linaril\v azul while l have iuilieatetl Yarinee whit-h liuiitml to ya'peeilie ous; 'alue-f of potential :unl resida may he usetl. l lo not wish to he lheae partiel-tlm' Values nor to the st rueturea illtotratetl.

lVliat l eonsuler as new Hire to seeure hy Letterl latent States istw* 1. telephone exehauLfe vaten eontprising a telephone line. a eonneetion terminal normally xli=eo|n|eeteil therefronna relay for eonneeting y,kahl eonneetion terlninul antl novel antl lent ill@ with Sairl relay. nhl nu-ee atnl the wintlin; !.otl Saisl relay lleiugf :ulapteil to he eonueeletl in `-huut of :l portion ol' one litnh of the telephone line. uu-an wherelov the eurl'enta l'rou'i aitl sourre through `.arid relay jar'lw. tht-relu' re`toring1v all up"V man? are restricted to circuits local to theex-A change, a cord connector terminating in a coiuiecting plug, source of current oonnected between the strands of said cord connector constituting the sole source for furnishing current for talking purposes, and means whereby the insertion of the connecting plug into the 'connection terminal sends current from said first mentioned source over a circuit including a talking strand of said cord connector, a terminal of: the connecting` lug7 a line contact of the telephone line, an the portion of a talking limb of the telephone line extending between sald line contact and said relay. g' 4 Q. A telephone exchange system comprising a telephone line a connection terminal iioiii'ually disconnected therefrom, a relay for .connecting said connection terminal with the line, a. source of current associated with said relay, a separate source of currcni adapted to be connected in the metallic circuit for talking purposes, means for opcraiiuig said relay from said l'lrst mentioned sourcewlien connection is made with the line by current flowing over a path includinga portion ot' the talking circuit, means wherebyY said relay does not receive current from said second source, and means for sending a calling current over the` line of the called subscriber only and at the saine time maintaining said relay in operative condition. i

tl. A telephone exchange system comprising a telephone line, a. normally disconnected talking contact of a spring Jack associated 'with the said line, a plug, a cord. circuit, a battery associated VWitl'iythe said circuit adapted to be included in the metallic circuitof `the line and constituting the sole `die :oni'icecd therefrom, a, central source of current associated with the line and adapted to be included in the metallic circuit of thc line` when a connection exists and constituting the sole source for furnishing curi'cnt to the substation transmitters for talking purposes, means for disconnecting said contact 'from the line when the line is not iii iur. a second source of current, means operated by current froni said second source over a. por-tion of the talking circuit to connect thc Contact with the line when the line is in use, means whereby the currents from said source 'through said relay are restrict- 4 metal .ic telephone line, a talking coned to circuits local to the exchange, and testing apparatus to cooperate with said contact lo indicate the condition of the line,

5. A telephone exchange system comprising a telephone line, a test terminal normally disconnected therefro1n :i relay for connecting said test terminal with the line, a source of current associated therewith, testing apparatus, a cord circuit terminatinr in a connecting plug, supervisory signa ing apparatus associated with the cord circuit, a second source of electricity associated with the cord circuit, means for closing the circuit of said second source over the telephone line to operate the sait supervisory apparatus, means whereby said relay does not receive current from said second source, and means for closing the circuit oi said first mentioned source through said relay when connection is made with the line. said .relay circuit including one of the main terminals of the connecting plug and a line contact of the telephone line with suitable return.

6. A, telephone ex'changc system comprising a telephone line, a cord circuit adapted to be included in a talking circuit, a line signal and a eut-oit' relay for the line, a source of current associated with said relay, means whereby the currents from said source through said relay are restricted to circuits localto the exchange, means for closing circuit froin said source through said relay over a. portion of one side of the talking circuit, including a portion of the telephone line a'nd the cord circuit, a second source for supplying current for talking purposes, connected in bridge of said c ord circuit and means whereby said relay does not receive current from said second source.

7. A telephone exchange system comprising a telcp ione liuc and aconnection terminal in the form of a spring jack, a conmeeting plug and a cord circuit, a central source of current associated with said circuit to furnish current for talking purposes,

supervisiiiy signal apparatus associated with vthe cord circuit a operated from said source of current, a relay actuated from a Second source of current by the insertion of said plugr into, and its withdrawal from, said Jack for controlling a eonnectionof said jack with said line, said relay being actuated by current tiowing over a Joi'tion of :i strand of thc cord circuit, ii talking contact ot the plug and jack and a portionof the telephone liuc and means whereby the currents from said second source are restricted to circuits local to the exchange.

8. A telephone exchange system comprising a telephone line, signal receiving mechanism for said line at the exchange, a cut-oil' relay for operation to render said mechamsm ineffective, an ungrounded source of current having a terminal connected with iso said cut-off relay, a plug and jack contact for closure by :in operator to establish a metallic circuit of said source through seid cut-oil relay to operate the same, :t second ,source of current associated with said line, said second source being grounded und having its` active. terminal connected in opposition to said first-mentioned source, und ineens for ctmnecling suid second Source to huid line whcrcli' tulkinor current is solei1 supplied to suitl line therefrom.

l). A telephone system comprising a telephone lintI und n cord-circuit for connection therewith, n pnir olf sources of electrical energy connected lo one strand of said cordcircuit, one of said sources only being oper ntivcly connected with the other strand of said circuit, u relay l() for said cord-circuit operated solely by current from one of said sources, 'u relay for said line operated solely by current from the other of said i sources, n second relay l1 for said cordcircuit included 1n u clrcint to receive current from both sind sources, and a metallic connection uniting terminals of opposed polux-ity of said sources.

l0. A telephone system comprising a telephone line and a cord-circuit for connection therewith, a, pair of Sources of electrcal'energy connected to nestmnd of said cordcircnit, one of Suid sdll''ccs only being operuiively connected with the other strand of said circuit, u, relay l0 for said cord-circuit operated solely by current from one of said sources, a relay 5 for said vline operated solely by current from the other of said sources, :i second relay 1l for sui'd cord-circuit included in a circuit to receive current from both said sources, a metallic connection uniting terminals of opposed polarity of said sources, und an operative earth con* nection for one of said sources only.

In witness whereof, I hereunto subscribe my naine this 14th dayof July 1906.

' HARRY G. VEBSTER.

vWitnesses:

A. H. Dyson, H.. C. Omis'rnn. 

